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101 lines
2.2 KiB
C++
101 lines
2.2 KiB
C++
//
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// Acorn.cpp
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// Clock Signal
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//
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// Created by Thomas Harte on 06/11/2016.
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// Copyright © 2016 Thomas Harte. All rights reserved.
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//
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#include "Acorn.hpp"
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using namespace Storage::Tape::Acorn;
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Parser::Parser() :
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::Storage::Tape::Parser<WaveType, SymbolType>(),
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crc_(0x1021, 0x0000) {}
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int Parser::get_next_bit(const std::shared_ptr<Storage::Tape::Tape> &tape)
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{
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SymbolType symbol = get_next_symbol(tape);
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return (symbol == SymbolType::One) ? 1 : 0;
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}
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int Parser::get_next_byte(const std::shared_ptr<Storage::Tape::Tape> &tape)
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{
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int value = 0;
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int c = 8;
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if(get_next_bit(tape))
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{
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set_error_flag();
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return -1;
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}
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while(c--)
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{
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value = (value >> 1) | (get_next_bit(tape) << 7);
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}
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if(!get_next_bit(tape))
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{
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set_error_flag();
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return -1;
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}
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crc_.add((uint8_t)value);
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return value;
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}
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int Parser::get_next_short(const std::shared_ptr<Storage::Tape::Tape> &tape)
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{
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int result = get_next_byte(tape);
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result |= get_next_byte(tape) << 8;
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return result;
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}
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int Parser::get_next_word(const std::shared_ptr<Storage::Tape::Tape> &tape)
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{
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int result = get_next_short(tape);
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result |= get_next_short(tape) << 8;
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return result;
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}
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void Parser::reset_crc() { crc_.reset(); }
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uint16_t Parser::get_crc() { return crc_.get_value(); }
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void Parser::process_pulse(Storage::Tape::Tape::Pulse pulse)
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{
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switch(pulse.type)
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{
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default: break;
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case Storage::Tape::Tape::Pulse::High:
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case Storage::Tape::Tape::Pulse::Low:
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float pulse_length = pulse.length.get_float();
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if(pulse_length >= 0.35 / 2400.0 && pulse_length < 0.7 / 2400.0) { push_wave(WaveType::Short); return; }
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if(pulse_length >= 0.35 / 1200.0 && pulse_length < 0.7 / 1200.0) { push_wave(WaveType::Long); return; }
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break;
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}
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push_wave(WaveType::Unrecognised);
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}
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void Parser::inspect_waves(const std::vector<WaveType> &waves)
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{
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if(waves.size() < 2) return;
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if(waves[0] == WaveType::Long && waves[1] == WaveType::Long)
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{
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push_symbol(SymbolType::Zero, 2);
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return;
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}
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if(waves.size() < 4) return;
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if( waves[0] == WaveType::Short &&
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waves[1] == WaveType::Short &&
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waves[2] == WaveType::Short &&
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waves[3] == WaveType::Short)
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{
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push_symbol(SymbolType::One, 4);
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return;
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}
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remove_waves(1);
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}
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